Here is the description from the TED website:

Using photos of oft-snapped subjects (like Notre Dame) scraped from around the Web, Photosynth (based on Seadragon technology) creates breathtaking multidimensional spaces with zoom and navigation features that outstrip all expectation. Its architect, Blaise Aguera y Arcas, shows it off in this standing-ovation demo. Curious about that speck in corner? Dive into a freefall and watch as the speck becomes a gargoyle. With an unpleasant grimace. And an ant-sized chip in its lower left molar. "Perhaps the most amazing demo I've seen this year," wrote Ethan Zuckerman, after TED2007. Indeed, Photosynth might utterly transform the way we manipulate and experience digital images.